1. Slide1: 50 Newton is about equal to 1. 10 lbs 2. 23 lbs 3. 50 lbs 4. 110 lbs 5. 250 lbs

2. Slide 2 What is a net force? 1.A force acting on an object 2.All the forces acting downward 3.The combination of all the forces 4.When all the forces cancel out

3. Slide 3 You throw a rock in space. What is required to keep the rock moving at a constant velocity? 1.A constant force while its moving 2.A very small force once its moving 3.nothing

4. Slide 4 A book is resting on a table. Since the book is not moving 1.There is not a force acting on it 2.The table is pushing up with a greater force than gravity is pulling down with 3.Gravity is pulling down with a greater force than the table is pushing up with 4.The net force on the book must be zero

5. 1.Move at a constant velocity 2.Continually change velocity 3.Move for a while at a constant velocity and then change velocity 4.It depends on how big the frictional forces are Slide 5 A constant (and not zero) net force is applied to a person on rollerblades. The person will…

6. Slide 6 There is a zero net force acting on a person on rollerblades. You could say 1.The person is not moving 2.The person is moving at a constant velocity (not zero) 3.The person is accelerating 4.Not enough information to tell

7. Slide 7 A person on rollerblades is pushed with a constant force of 10 N and experiences an unknown force of friction. If the person moves at a constant velocity of 2 m/s, you could say… 1.friction = 0 N 2.friction = 5 N 3.friction= 10 N 4.friction = 20 N

8. Slide 8 To change the velocity of an object, you need 1.forces 2.unbalanced forces 3.inertia 4.nothing